Server overhaul: one test harness in tests/common for every test binary

core_api/common.rs becomes tests/common/mod.rs and sync_api/m4.rs tests/common/sync_fixtures.rs; each binary
includes them through #[path] (the binaries of SPEC §14.7 stay as they are). TempDir's Default moves into the
harness instead of three copies; the skeleton helpers take ids, tokens and TempDir from it. Milestone wording in
test docs and the server README replaced by what the code does; README seams and test layout updated.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TQd3pEP9UeN2uifbHknQ7B

server/crates/kvitt-server/tests/sync_api/audit.rs

@@ -1,10 +1,10 @@
-//! The real audit writer (SPEC §14.4.7, FR-12) through M3's recurring generation and through sync: source, actor,
+//! The real audit writer (SPEC §14.4.7, FR-12) through the recurring generation and through sync: source, actor,
 //! times and append-only entries.
 
 use serde_json::json;
 
 use crate::common::*;
-use crate::m4::*;
+use crate::sync_fixtures::*;
 
 #[tokio::test]
 async fn generation_writes_recurring_audit_with_server_now_and_no_device() {

server/crates/kvitt-server/tests/sync_api/conflicts.rs

@@ -3,7 +3,7 @@
 use serde_json::json;
 
 use crate::common::*;
-use crate::m4::*;
+use crate::sync_fixtures::*;
 
 const T0: &str = "2026-10-17T10:00:00.000Z";
 
@@ -24,7 +24,7 @@ fn delete(id: &str, at: &str) -> serde_json::Value {
 #[tokio::test]
 async fn both_users_edit_offline_the_later_updated_at_wins_in_either_arrival_order() {
     for later_arrives_first in [true, false] {
-        let app = crate::m4::app().await;
+        let app = crate::sync_fixtures::app().await;
         let id = new_id();
         push_one(&app, &admin_token(), exp(expense(&id, T0))).await;
         let anna = exp(edit(&id, "2026-10-17T11:00:00.000Z", "Anna's"));
@@ -50,7 +50,7 @@ async fn both_users_edit_offline_the_later_updated_at_wins_in_either_arrival_ord
 #[tokio::test]
 async fn one_deletes_the_other_edits_delete_wins_regardless_of_order_and_timestamps() {
     // Delete first, then a newer edit: rejected deleted.
-    let app = crate::m4::app().await;
+    let app = crate::sync_fixtures::app().await;
     let id = new_id();
     push_one(&app, &admin_token(), exp(expense(&id, T0))).await;
     accepted(
@@ -69,7 +69,7 @@ async fn one_deletes_the_other_edits_delete_wins_regardless_of_order_and_timesta
     .await;
     rejected(&r, "deleted");
     // Edit first, then an older delete: applied.
-    let app = crate::m4::app().await;
+    let app = crate::sync_fixtures::app().await;
     let id = new_id();
     push_one(&app, &admin_token(), exp(expense(&id, T0))).await;
     accepted(
@@ -94,7 +94,7 @@ async fn one_deletes_the_other_edits_delete_wins_regardless_of_order_and_timesta
 
 #[tokio::test]
 async fn same_user_on_two_devices_is_lww_per_row() {
-    let app = crate::m4::app().await;
+    let app = crate::sync_fixtures::app().await;
     // A second, non-revoked device of the admin.
     let second = token('S');
     app.insert_device(
@@ -129,7 +129,7 @@ async fn same_user_on_two_devices_is_lww_per_row() {
 #[tokio::test]
 async fn an_expense_in_an_account_deleted_meanwhile_is_reference_not_found_archived_category_accepted()
  {
-    let app = crate::m4::app().await;
+    let app = crate::sync_fixtures::app().await;
     tombstone(&app, "accounts", ACCOUNT_1).await;
     rejected(
         &push_one(&app, &admin_token(), exp(expense(&new_id(), T0))).await,
@@ -150,7 +150,7 @@ async fn an_expense_in_an_account_deleted_meanwhile_is_reference_not_found_archi
 async fn epoch_recovery_re_push_of_identical_rows_comes_back_stale_with_equal_content() {
     // §14.4.8: after a restore the phone re-pushes everything; identical rows are stale with current equal to the
     // pushed client-writable fields (the phone treats that as accepted), missing rows are inserted.
-    let app = crate::m4::app().await;
+    let app = crate::sync_fixtures::app().await;
     let kept = new_id();
     let entity = expense(&kept, T0);
     push_one(&app, &admin_token(), exp(entity.clone())).await;

server/crates/kvitt-server/tests/sync_api/e2e.rs

@@ -6,7 +6,7 @@ use std::sync::Arc;
 use kvitt_server::push::{PushHub, PushType};
 
 use crate::common::*;
-use crate::m4::*;
+use crate::sync_fixtures::*;
 
 #[tokio::test]
 async fn create_on_device_a_pull_on_device_b_row_audit_and_one_push() {

server/crates/kvitt-server/tests/sync_api/m4.rs

@@ -1,225 +0,0 @@
-//! M4 additions to M3's harness: an app with the real audit writer, entity and mutation builders, push and pull
-//! helpers, and audit row access. Shared by the `sync_api`, `push_fcm` and `scheduler_daily` test binaries.
-
-use std::sync::Arc;
-
-use axum::http::Method;
-use kvitt_server::audit::SqlAuditWriter;
-use kvitt_server::push::PushQueue;
-use kvitt_server::router;
-use serde_json::{Value, json};
-use uuid::Uuid;
-
-use crate::common::*;
-
-/// The household of `TestApp::household` with accounts ACCOUNT_1 (50/50) and ACCOUNT_2 (50/50) and the real audit
-/// writer; pushes go to the recording queue.
-pub async fn app() -> TestApp {
-    let mut app = TestApp::household().await;
-    app.insert_account(ACCOUNT_1, "Vardag", "2026-10-01T00:00:00.000Z", 5000)
-        .await;
-    app.insert_account(ACCOUNT_2, "Resor", "2026-10-02T00:00:00.000Z", 5000)
-        .await;
-    app.state.audit = Arc::new(SqlAuditWriter);
-    app.router = router::router(app.state.clone());
-    app
-}
-
-/// Replaces the push queue (and rebuilds the router).
-pub fn with_push(app: &mut TestApp, push: Arc<dyn PushQueue>) {
-    app.state.push = push;
-    app.router = router::router(app.state.clone());
-}
-
-pub fn new_id() -> String {
-    Uuid::now_v7().to_string()
-}
-
-/// A pushed expense: 412,00 kr ICA Maxi in ACCOUNT_1, groceries, paid by the admin, mode default 50/50.
-pub fn expense(id: &str, updated_at: &str) -> Value {
-    json!({
-        "id": id, "account_id": ACCOUNT_1, "category_id": GROCERIES, "amount_ore": 41200,
-        "description": "ICA Maxi", "notes": "", "expense_date": "2026-10-16", "payer_user_id": ADMIN_ID,
-        "split_mode": "default",
-        "splits": [
-            {"user_id": ADMIN_ID, "share_ore": 20600, "share_bp": 5000},
-            {"user_id": MEMBER_ID, "share_ore": 20600, "share_bp": 5000}
-        ],
-        "created_at": updated_at, "updated_at": updated_at, "deleted_at": null
-    })
-}
-
-/// A pushed settlement: the member pays the admin 500,00 kr, 300 to ACCOUNT_1 and 200 to ACCOUNT_2.
-pub fn settlement(id: &str, updated_at: &str) -> Value {
-    json!({
-        "id": id, "from_user_id": MEMBER_ID, "to_user_id": ADMIN_ID, "amount_ore": 50000,
-        "settlement_date": "2026-10-16", "note": "",
-        "allocations": [
-            {"account_id": ACCOUNT_1, "amount_ore": 30000}, {"account_id": ACCOUNT_2, "amount_ore": 20000}
-        ],
-        "created_at": updated_at, "updated_at": updated_at, "deleted_at": null
-    })
-}
-
-/// One mutation with a new mutation id.
-pub fn mutation(entity_type: &str, entity: Value) -> Value {
-    json!({"mutation_id": new_id(), "entity_type": entity_type, "entity": entity})
-}
-
-pub fn exp(entity: Value) -> Value {
-    mutation("expense", entity)
-}
-
-pub fn set(entity: Value) -> Value {
-    mutation("settlement", entity)
-}
-
-/// `POST /sync` with these mutations.
-pub async fn push(app: &TestApp, tok: &str, mutations: Vec<Value>) -> Reply {
-    app.call(
-        Method::POST,
-        "/sync",
-        tok,
-        Some(json!({ "mutations": mutations })),
-    )
-    .await
-}
-
-/// `POST /sync` with one mutation; asserts 200 and returns its result.
-pub async fn push_one(app: &TestApp, tok: &str, mutation: Value) -> Value {
-    let reply = push(app, tok, vec![mutation]).await;
-    assert_eq!(reply.status, 200, "{}", reply.text());
-    reply.json["results"][0].clone()
-}
-
-/// `GET /sync`.
-pub async fn pull(app: &TestApp, tok: &str, since: i64, limit: Option<i64>) -> Reply {
-    let path = match limit {
-        Some(l) => format!("/sync?since={since}&limit={l}"),
-        None => format!("/sync?since={since}"),
-    };
-    app.call(Method::GET, &path, tok, None).await
-}
-
-/// Asserts an accepted result for `entity_id` and returns its entity.
-#[track_caller]
-pub fn accepted(result: &Value) -> Value {
-    assert_eq!(result["status"], "accepted", "{result:#}");
-    assert_eq!(result["server_version"], result["entity"]["server_version"]);
-    result["entity"].clone()
-}
-
-/// Asserts a rejected result with `reason`.
-#[track_caller]
-pub fn rejected(result: &Value, reason: &str) {
-    assert_eq!(result["status"], "rejected", "{result:#}");
-    assert_eq!(result["reason"], reason, "{result:#}");
-    assert!(result["message"].is_string());
-    let keys: Vec<_> = result.as_object().unwrap().keys().cloned().collect();
-    assert_eq!(
-        keys,
-        [
-            "current",
-            "entity_id",
-            "entity_type",
-            "message",
-            "mutation_id",
-            "reason",
-            "status"
-        ]
-    );
-}
-
-/// One audit row as stored.
-#[derive(Debug, Clone, PartialEq)]
-pub struct AuditRow {
-    pub action: String,
-    pub source: String,
-    pub actor_user_id: String,
-    pub actor_device_id: Option<String>,
-    pub client_at: String,
-    pub server_at: String,
-    pub changes: Value,
-    pub server_version: i64,
-}
-
-#[derive(sqlx::FromRow)]
-struct RawAudit {
-    action: String,
-    source: String,
-    actor_user_id: String,
-    actor_device_id: Option<String>,
-    client_at: String,
-    server_at: String,
-    changes: String,
-    server_version: i64,
-}
-
-/// The audit rows of an entity, oldest first.
-pub async fn audit_of(app: &TestApp, entity_id: &str) -> Vec<AuditRow> {
-    let rows: Vec<RawAudit> = sqlx::query_as(
-        "SELECT action, source, actor_user_id, actor_device_id, client_at, server_at, changes, server_version \
-         FROM audit_log WHERE entity_id = ? ORDER BY server_version",
-    )
-    .bind(entity_id)
-    .fetch_all(&app.state.db)
-    .await
-    .unwrap();
-    rows.into_iter()
-        .map(|r| AuditRow {
-            action: r.action,
-            source: r.source,
-            actor_user_id: r.actor_user_id,
-            actor_device_id: r.actor_device_id,
-            client_at: r.client_at,
-            server_at: r.server_at,
-            changes: serde_json::from_str(&r.changes).unwrap(),
-            server_version: r.server_version,
-        })
-        .collect()
-}
-
-/// The pushes enqueued so far, as `(type, entity id, actor, count)`.
-pub fn pushes(app: &TestApp) -> Vec<(String, Option<String>, String, u32)> {
-    app.push
-        .0
-        .lock()
-        .unwrap()
-        .iter()
-        .map(|m| {
-            (
-                m.push_type.as_str().to_owned(),
-                m.entity_id.map(|id| id.to_string()),
-                m.actor_user_id.to_string(),
-                m.count,
-            )
-        })
-        .collect()
-}
-
-/// `count(*)` of a table.
-pub async fn count(app: &TestApp, table: &str) -> i64 {
-    sqlx::query_scalar::<_, i64>(sqlx::AssertSqlSafe(format!("SELECT count(*) FROM {table}")))
-        .fetch_one(&app.state.db)
-        .await
-        .unwrap()
-}
-
-/// The current `sync_sequence` value.
-pub async fn sequence(app: &TestApp) -> i64 {
-    app.scalar_i64("SELECT value FROM sync_sequence").await
-}
-
-/// Marks a row deleted directly (an account or category deleted through REST meanwhile).
-pub async fn tombstone(app: &TestApp, table: &str, id: &str) {
-    let version = app.next_version().await;
-    sqlx::query(sqlx::AssertSqlSafe(format!(
-        "UPDATE {table} SET deleted_at = ?, server_version = ? WHERE id = ?"
-    )))
-    .bind(NOW)
-    .bind(version)
-    .bind(id)
-    .execute(&app.state.db)
-    .await
-    .unwrap();
-}

server/crates/kvitt-server/tests/sync_api/main.rs

@@ -1,13 +1,14 @@
-//! M4 sync integration tests: every rule of SPEC §14.4.2 (pull) and §14.4.4 (push steps 1 to 12), each rejection
+//! Sync integration tests: every rule of SPEC §14.4.2 (pull) and §14.4.4 (push steps 1 to 12), each rejection
 //! reason of §14.4.6, the §9.10 conflict cases, batch limits, `cursor_ahead`, the epoch, the 14-day offline scenario
 //! (AC-15.6), the audit writer (§14.4.7), `rotate-epoch` (§10.4), the end-to-end path device A push → device B pull,
-//! and the orchestrator-assigned `serve` fixes (ConnectInfo for the rate limiter, `/i/` HTML 404).
+//! and `serve` itself (ConnectInfo for the rate limiter, `/i/` HTML 404, the shutdown drain).
 //!
-//! Reuses M3's harness (`tests/core_api/common.rs`) with the real `SqlAuditWriter` swapped in (`m4.rs`).
+//! The harness is `tests/common/`, with the real `SqlAuditWriter` swapped in by `sync_fixtures`.
 
-#[path = "../core_api/common.rs"]
+#[path = "../common/mod.rs"]
 pub mod common;
-pub mod m4;
+#[path = "../common/sync_fixtures.rs"]
+pub mod sync_fixtures;
 
 mod audit;
 mod conflicts;
@@ -16,9 +17,3 @@ mod offline;
 mod pull;
 mod push_rules;
 mod serve;
-
-impl Default for common::TempDir {
-    fn default() -> Self {
-        Self::new()
-    }
-}

server/crates/kvitt-server/tests/sync_api/offline.rs

@@ -6,7 +6,7 @@ use kvitt_server::time::{format_ts, parse_ts};
 use serde_json::{Value, json};
 
 use crate::common::*;
-use crate::m4::*;
+use crate::sync_fixtures::*;
 
 #[tokio::test]
 async fn fourteen_days_offline_200_changes_all_sync() {

server/crates/kvitt-server/tests/sync_api/pull.rs

@@ -4,7 +4,7 @@ use axum::http::Method;
 use serde_json::Value;
 
 use crate::common::*;
-use crate::m4::*;
+use crate::sync_fixtures::*;
 
 const T1: &str = "2026-10-17T11:00:00.000Z";
 const ARRAYS: [&str; 7] = [

server/crates/kvitt-server/tests/sync_api/push_rules.rs

@@ -5,7 +5,7 @@ use axum::http::Method;
 use serde_json::{Value, json};
 
 use crate::common::*;
-use crate::m4::*;
+use crate::sync_fixtures::*;
 
 /// A change applied to a pushed entity.
 type Mutator = Box<dyn Fn(&mut Value)>;